export interface Task {
  id: string;
  title: string;
  description: string;
  type: 'daily' | 'weekly' | 'monthly' | 'challenge' | 'community';
  reward: {
    greenEnergy: number;
    carbonReduction: number;
    trees?: number;
    waterQuality?: number;
  };
  progress: number;
  completed: boolean;
  deadline?: Date;
  criteria: {
    type: 'steps' | 'energy' | 'action' | 'participation';
    target: number;
    current: number;
  };
} 